I have two strains of RIR in seperate pens. One is a hatchery stock backcrossed 2 generations. The other is hatchery stock. This far they both are very productive as far as egg laying goes. What do I get out of crossing the two strains and then selecting for breeders? would i be better off picking one strain and selectively line breeding them? I have heard one opinion that crossing strains is a waste of time. Advice from experienced breeders please?